In commercial entertainment systems, which are used in aircraft for example for on-board entertainment, as a result of a protected architecture, for example by building output units into the seats and/or protected networks which are only accessible to specific technicians and engineers, very high-quality data content can be provided. This type of data content is for example audio and/or video content (e.g. music clips, films, series etc.), which is shown in an airline hospitality window, e.g. is shown to the passengers during flights. This means that the data content is already provided on these types of entertainment system in aircraft even before it appears on the market, e.g. on a DVD etc. or very shortly after its release in the cinema for example.
The trend in the market of switching from permanently installed output units (e.g. screens etc.) in entertainment systems to personal entertainment devices (PED) such as smart phones, tablet PCs and/or laptops for example, or of making the content of entertainment systems directly accessible to a user's terminal, means that the high-quality data content is no longer protected by a restricted system architecture of the entertainment system for example. This can result in owners of the data content or owners of rights to the data content (e.g. film studios, rental companies, etc.) only reluctantly wanting or even not wanting at all to make it available in an airline hospitality window. To also enable the highest possible quality data content such as audio and/or video content for example to continue to be offered it will thus become necessary to find new or alternate protection mechanisms which make availability possible on personal entertainment devices as output units but also provide protection against unauthorized copying and/or playback.
In today's entertainment systems protection of the data content is provided by a complete isolation of the networks and servers, which are only accessible to authorized personnel or authorized technicians for example. The data content is output and displayed for example on in-flight entertainment systems on output units attached to the roof of the cabin or built into the seat. Output to personal entertainment devices or private mobile terminals of the users such as smart phones, tablet PCs etc. is not possible in any event on the systems. This means however that these systems are relatively inflexible and display of the data content is linked to one seat in the aircraft for example.
If personal entertainment devices or mobile terminals are used as output units various methods and widely used protection mechanisms have become available in the interim to protect against unauthorized usage (e.g. playing, copying, etc.). Such already widely used protection mechanisms are e.g. Digital Rights Management (encryption), conditional access, (seat-based) watermarking or identification by means of what are known as digital watermarks, client hardening, deactivation of video outputs etc.
Digital Rights Management (DRM) is to be understood as methods and/or systems with which use or if necessary also distribution of digital content can be controlled. Digital Rights Management (DRM) or secure use is employed above all with audio and/or video data content but also with software, electronic documents and/or electronic books. DRM makes it possible for providers of data content to carry out usage control for their data content, principally by developing new payment options (e.g. granting of licenses, authorizations etc.) and thus allowing billing for usage rights to data content instead of the data content itself.
This enables the use of data content to be restricted to a usage agreement made previously for example. With DRM for example audio and/or video data content etc. is encrypted before digital transmission to an output unit. I.e. the data stream for the transmission of the data content is encrypted by the DRM system. The encrypted data stream is then transmitted to the output unit and then directly decrypted on the output unit of the respective users if they have the corresponding authorizations and/or checking of the authorizations by the DRM system etc. However a disadvantage of Digital Rights Management is that, for further presentation of the data content on the output unit, the data content must be available completely unencrypted. In such cases there is then the danger of the data content (e.g. video content before availability on DVDs etc.) e.g. during the reproduction on the output unit for example being (digitally) filmed or copied and thus being able to be used again contrary to the usage agreement.
So-called conditional access or an access system is a method of protection for data content in which specific criteria must be complied with, before access to the data content is provided. Conditional Access is for example frequently used in the area of digital television, especially with pay-per-view satellite TV broadcasters (so-called pay-TV). Thus in the common access method used for digital television, by which the data content is encrypted and decrypted, a continuously changing control word is used, through which the data content can be decrypted on the receiver side. This control word is made available by a common-access system to an authorized output unit and makes sure that only defined recipients or output units will be addressed and receive the control word. On the receiver side or the output side a user-independent conditional access module and a user-dependent smartcard are usually used in the output unit. Thus conditional access—especially in conjunction with entertainment systems in aircraft for example—usually have a disadvantage of the terminals having to be equipped with additional units such as common access modules and smartcards for example. In addition these devices do not prevent the user copying or storing the data content as soon as this is encrypted on the respective output unit.
A further option for protecting data content is what is known as digital watermarking. With this method imperceptible markings are usually recorded in the carrier media of the data content, such as images, videos, 3D data, audio material and/or texts for example. These digital watermarks can then be read out by means of computer-based methods and used for various purposes (e.g. tracing owner rights violations, verification of data integrity and/or authenticity, etc.) However the disadvantage of digital watermarking is that it does not represent a direct protection mechanism for the data content. It only allows owner rights violations to be proved and/or possible illegal copies of data content or the playback thereof to be identified.
Client hardening usually involves an output unit such as a client for example, from which contact is made in a computer system with a server in order to obtain data content, applications and/or services from this server to protect against unauthorized manipulations (e.g. installation or de-installation of client software, applications, protected services and/or data content etc.). In an output unit for which client hardening has been employed a change to the software and/or data contents (e.g. deletion, copying, etc.) can now only be carried out by authorized persons (e.g. administrator etc.). No further changes and/or manipulation can be performed by unauthorized persons at this output unit, e.g. to the configured protection facilities and/or the software. However the disadvantage of client hardening is that an authorized administrator must always be available for creation of new data content for example and/or for changes. Thus client hardening—especially in the area of entertainment systems—is relatively complex and cost-intensive and also inflexible, since for example private terminals of a user cannot be used as an output unit.
Furthermore unauthorized copying of data content made available can also be prevented by deactivation of video outputs, of the output unit for example. However this deactivation must be carried out at each output device before it is used. In addition this does not prevent the data content being filmed or recorded directly from the output unit by means of a recording device (e.g. camera, smart phone, etc.) and then for example played back or duplicated in an unauthorized manner.